Just like some people tan better--easier, faster, what-have-you, some plants color up better than others. One b.b. plant might color beautifully and another be kind of a dud in the fall color dept. I haven't heard anything about the soil having much effect, but microclimates would definately influence this. Having said that it could just be the temp. and moisture conditions this particular year.

I have the same question too! I have several burning bushes that were planted about 4 years ago. They are growing beautifully and look very healthy. They also get a good amount of sun too. However, they will at the most have a few red leaves, while the rest are just bronze or purple at the tips and that's it! It's been like this for the last few years. Every other burning bush in my area has turned bright red already!!! I too would love to know if there is anything I can do about this...

Mine gets no sun - really - like none... and I've just been informed by leftwood that that is in fact what is blazing red in my front shade garden. I neglect that bed, only sort of weed it and trim it up. Used to prune the thing too which I now won't do as I know what it is and it has a nice shape. Mine even "fruited"/bloomed this time.

I know, I'm of no use at all! But it just started blazing within the last week or so.
-Marie

Everything Leaves said is true, although BB are known for their color and I think one would be hard pressed to find a true dud. More likely it's the particular environment. Most people will find that unless the bush is having problems that need attention, leaving the bush alone and not babying it will be best. I will also testify that age and maturity can have something to do with fall color.

That said, even though this fall seems rather normal, I have noticed a good portion of non-colorings. In my own yard, this is the first time my Carolina Alspice's leaves froze green, and my Miyabe maple always shows at least some color, and this time none. My Smoke tree(not Smoke bush) usually has at least two weeks of fall color, and this time only one. Even my River birch had some of its leaves freeze green for the first time. I have three different types of viburnums that are in full color now.

Same issue here-- there are two of 'em on the west side of our house, and they are definitely mature-- they used to turn red when they were younger but now they just stay green until the leaves drop off.

They're in partial shade and next to the stone wall of the house so our theory is that the stone wall keeps them warm enough at night that they don't change now.

I have a similar problem. The bottom half of the bush is dark red, the top half is green. 2 winters ago rabbits chewed off most of it so I pruned it back to shape in the spring. It was smaller last year but it turned red. Last winter was very mild and a few branches dried out. This spring I cut the dead branches off. The bush pretty much exploded and had a great growth this year, it's about 6 feet tall. It's not looking very nice but I wanted to leave it to grow for now. The bottom 1.5 foot is dark red, the 2 branches that were chewed off and didn't really have a great growth, and the top part does not look like it is going to change color, which is where all the new hight happened this year. Not sure what to do with it. I was thinking that it is a hybrid and some branches reverted back to the original colorless state? If that's the case I would have to cut all of the green off, but I don't know if burning bushes are actually made hybrid. I will wait confirmation on that before I get to it with the branch cutter again.
I will attach the picture I just took. The red leaves are falling off now too. We had the first frost a few weeks ago.

Euonymus are usually cutting grown, or the odd seed, but never grafted. I don't see anything wrong with yours. There is just a different chemical makeup (temporarily) in the new fast growth of this season. This, probably including a hormone imbalance compared to the older part, is delaying all the changes that normally take place at this time of year. Next year it should be back to its normal self, assuming you don't have to do more drastic pruning. It doesn't look like you're getting any corky wings on the bark, either. This could be a normal age thing, or if it is different than before, it could be for the same reason.